Alden



M. ALDEN INDICATOR LIGHT Aug. 20, 1957 2 Shets-Sheet 1 Filed March 26', 1954 [ml/6m? mazzawflm Y Aug. 20, 1957 ALDEN 7 2,803,816

INDICATOR LIGHT Filed March 26, 1954 2 Sheets-Sheet 2 I f fnvlzior' MlZZ'OIZ llden gyfiw, Qa/J/MW United States Patent 2,803,816 INDICATOR LIGHT Milton Alden, Needham, Mass. 7 Application March 26, 1954, Serial No. 418,980

2 Claims. (Cl. 340381) This application constitutes a continuation-in-part of my copending application Serial No. 281,779, filed April 11, 1952, now Patent No. 2,742,636.

This invention relates to electrical indicator lights of the type which may be mounted on an electrical panel for the purpose of indicating the operation or failure of electrical circuits.

Although the use of pilot or indicator lights for electric circuits is old and well known in the art, the large size, expensive power consumption and difiiculty of maintenance of the available lights has limited their use. Accordingly it is an object of the present invention to provide an indicator lamp structure which is small in size and inexpensive, simple in design and yet affords good electrical connections.

According to the present invention the lamp is enclosed in an insert adapted to be engaged in a tubular socket of insulating material, the socket having a contact at its open end and the insert having an annular shoulder facing the socket and, adjacent the shoulder, contact means connected to a lamp terminal and urged against the socket contact by the shoulder when the insert engages in the socket.

These and other objects and aspects will be apparent from the following description of a specific embodiment of the invention which refers to a drawing wherein:

Fig. 1 is a front view of the indicator light;

Fig. 2 is a side view of the light shown in Fig. 1;

Fig. 3 is a side view taken at right angles to the View in Fig. 2;

Fig. 4 is a side view similar to Fig. 2 showing the diffuser and lamp removed from the body; 7

Fig. 5 is an enlarged sectional view on line 5-5 of Fig. 3;

Fig. 6 is an exploded sectional view like Fig. 4 of a modified form of the invention; and

Figs. 7 and 8 are end views of the socket and insert shown in Fig. 6.

As is best shown in Fig. 5, the indicator light consists of a body 10 molded from an electrically non-conducting material such as a suitable plastic in the form of a hollow cylinder whose lower end is closed by an integral head 12. The opposite end of the body 10 is open to form a socket for a small lamp L as will be described in detail hereinafter. Near the bottom of the socket is a disc 14 of plastic or other non-conducting material having a centrally disposed aperture therethrough. The bare end of an insulated conductor 16 is threaded through the aperture in the disc 14 and secured by means of a drop of solder 18. The conductor 16 is brought out through the head 12 by the conduit formed by the hole in a hollow rivet 20 whose function is described below. Interposed between the inner face of the head 12 and the bottom of the disc 14 is a spring 22 which yieldably urges the disc upwardly so that the drop of solder 18 acts as a spring loaded contact engaging the central terminal 24 of the lamp L.

The other connection to the lamp L is made through a metal ring 26 which is molded in the body 10 near the upper end of the socket immediately below internal threads whose function will appear hereinafter. In this position the ring 26 acts as a second contact which engages four tabs 32 extending outwardly from the upper end of the sleeve terminal 34 which forms the base of the lamp L. The bare end of a second insulated conductor 28, which is molded in the body 10, is soldered to the ring 26 as at 30.

Light rays from the lamp L are dispersed by a diifuser 36 of a translucent material of a suitable plastic such as nylon which is molded about the glass envelope of the lamp so that only the base thereof protrudes as is best shown in Fig. 4. The diffuser 36 is preferably a prism having sixteen or more sides 38 which break up any incident external light falling thereupon thereby minimizing the possibility of a false indication when the lamp is not energized. The upper end of the diffuser 36 is provided with a plurality of serrations forming facets 40 which correspond in number with the sides of the prism which facets perform the similar function of breaking up incident light.

The portion of the diffuser 36 adjacent the lamp base is provided with threads 42 (Fig. 4) which engage the internal threads in the body 10 so that the tabs 32 of the lamp sleeve terminal 34' are brought into contact with the ring 26 and the central terminal 24 engages the spring loaded contact 18 to complete the circuit to the lamp L. It will be apparent that this'arrangement makes it possible to use the diffuser 36 as a knob or handle for removing the lamp L and diffuser as a unit from the front of a panel P (Fig. 2.) wherein the body It is mounted as described hereinafter.

In mounting the indicator lamp an aperture having diameter slightly greater than that of the body 10 is drilled or otherwise provided in the panel P and the body inserted therein until the bottom of a flange 42, which extends radially from the upper end of the body 10, is in contact with the front surface of the panel. The body 10 is restrained in the panel aperture by means of a U-shaped clip of a resilient material whose leg portions 44 lie on either side of the body. The leg connecting portion 46 of the clip is secured to the body head 12 by means of the above-mentioned hollow rivet 20. Each of the leg portions 44 is provided with two tabs or fingers 48 which are struck outwardly from the respective leg portions so that the free ends of the tabs are directed towards the ends of the leg portions (or upwardly as yiewed in the drawing). As the body 10 is inserted in the panel aperture the leg portions 44 and the fingers 48 are bent inwardly until the fingers are beyond the back surface of the panel P whereupon the fingers spring outwardly so that the free ends thereof engage the back surface to lock the body in position.

As shown in Figs. 6 to 8 the simplified indicator light includes an insert or closure member 60 and a socket or recessed body 61. The insert comprises a cylindrical lens 62 and a tubular threaded plug 63. When the lens 62 and plug 63 are joined by threaded engagement the lamp 64 is enclosed and supported within the lens and plug. A contact ring 67 is loosely held against an annular shoulder 68 on the plug 63 by one of the wires or terminals 66 of the lamp 64, this terminal wire 66 being soldered to the ring 67. The other terminal wire 66 is connected through a grommet 69 extending through the end of the plug 63 to a contact comprising a spot of solder 70 concentric with the lens and plug.

The socket 61 comprises a tubular body 71 of insulating material having a recess 72. The open end of the recess is threaded at 73 to receive the threaded portion of the plug 63. Molded or press fitted at the open end of the recess 72 is another ring contact 74 disposed con- '77 is urged toward the open end of the recess 72 by a coil :spring 79.

As in the embodiment shown in Figs. 1 to 5 the lens 62, lamp, ring contact 67 and axial contact 70 are formed as a detachable unit. When the insert unit is screwed into the socket 61 the insert ring contact 67 is held against 'the ring contact 74 of the socket 61 by the annular shoulder 68, while the solder spot 70 makes contact with the concentric solder spot 78 on the disk 77, thus completing a circuit from the lead wires 75 to the lamp 64.

One further aspect of the present invention is my discovery that nylon has unexpected advantages as an enclosure and lens in miniature indicator lights. In the present structure its heat resistant properties permit the lens to fit snugly about the lamp thus affording a substantial economy of space without being subject to cracking or other deterioration due to heat. A further advantage of the nylon lens is its characteristic of being highly refractive and translucent for internal light from the lamp while being relatively opaque to incident external light. Preferably, but not necessarily, the transparency of the lamp to external light is reduced by adding any suitable coloring agent such as a dyestufi. As a result the lens is dull and unnoticeable when the lamp is off, but appears uniformly brilliant throughout a very wide angle, substantially 180, when the lamp is lighted.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims. 1

I claim:

1. In an electrical indicator for attachment in a socket, the combination of a lamp having an envelope and terminals, and a body of translucent, insulating molded plastic material including a lens portion extending at least over one end and the adjacent sides of the envelope for protecting the lamp transmitting light from the lamp throughout an angle of substantially said body including a molded portion about the lamp so as to support said lamp and terminals, and said lens portion being formed of nylon having the characteristic of being highly refractive and translucent to light from the lamp while being relatively opaque to incident external light so that the lens is dull and unnoticeable when the lamp is off but appears uniformly brilliant throughout a very wide angle when the lamp is lighted.

2. In an electrical indicator for attachment in a socket, the combination of a lamp having an envelope and terminals, and a body of translucent, insulating molded plastic material including a lens portion extending at least over one end and the adjacent sides of the envelope for protecting the lamp transmitting light from the lamp throughout an angle of substantially 180, said body including a molded portion about the lamp so as to support said lamp and terminals, and said lens portion being formed of nylon containing a coloring agent.

References Cited in the file of this patent UNITED STATES PATENTS 1,617,720 Morris Feb. 15, 1927 2,088,559 Kollsman July 27, 1937 2,339,196 Robbins Jan. 11, 1944 1 2,340,053 Grimes Jan. 25, 1944 

